You have to replace the backup battery. As for the display, connect the laptop to an external display to see if the issue remains.

It's getting that far and looks like it's mostly working so it's worth a go.
The video card is separate and I've found once or twice that the connector can need re-seating, this one here started displaying properly after I reseated the video card:

I was disappointed since I have a 400CDT video card in my spares and wanted to use it but then didn't need it at all.

Thermalwrong wrote on 2024-09-22, 18:00:

It's getting that far and looks like it's mostly working so it's worth a go. The video card is separate and I've found once or […]
Show full quote

It's getting that far and looks like it's mostly working so it's worth a go.
The video card is separate and I've found once or twice that the connector can need re-seating, this one here started displaying properly after I reseated the video card:

The attachment 355823175623_36de11fe640561b94eb2286303c851d6.jpg is no longer available

I was disappointed since I have a 400CDT video card in my spares and wanted to use it but then didn't need it at all.

ok cool thanks for your answer 😀

Yes,I agree too.I have the same problem and re-seating the video card fixed the issue.

i bought it i will let you know when i receive it. and i will tell you what the problem is. Thanks a lot guys without your comments i would have not buy it.
It should take some days for delivery. Have a nice day guys 😀

Hi ! I received it. We cleaned the video card, we cleaned the 3 socket with cable. Same problem. We heat the memory ram chip and all other chips. Same problem. I will to buy another video card. We dont have other idea. When we push on memory ram chip the screen glitched more so maybe it was ram chip.
Anyway i will but another video card, maybe there is it a safe web store:

https://www.impactcomputers.com/products/toshiba-p000208290

That's not good.If the problem is not on the bios,have you tried reinstalling windows or safe mode?

APOPAP wrote on 2024-10-08, 05:00:

That's not good.If the problem is not on the bios,have you tried reinstalling windows or safe mode?

no i will try later

But windows boot logo screen is glitched too so i dont think windows will be ok with another partition.

But thanks for the idea

renejr902 wrote on 2024-10-07, 19:33:

Anyway i will but another video card, maybe there is it a safe web store:

https://www.impactcomputers.com/products/toshiba-p000208290

Yes this store is safe, but if you see "Ships within 3-5 days", that's mean nothing available in stock 🙁

MAZter wrote on 2024-10-08, 10:19:

renejr902 wrote on 2024-10-07, 19:33:

Anyway i will but another video card, maybe there is it a safe web store:

https://www.impactcomputers.com/products/toshiba-p000208290

Yes this store is safe, but if you see "Ships within 3-5 days", that's mean nothing available in stock 🙁

ok thanks a lot for your answer 😀
and you are right the item is not in stock

Might be a vram problem? If it works with some video modes?

Have you tried messing with the bios settings or start just the command prompt ?

APOPAP wrote on 2024-10-08, 19:32:

Have you tried messing with the bios settings or start just the command prompt ?

yes i messed with every setting. and i tried windows in safe mode.

its ok in Command prompt. I didnt try a dos game yet

renejr902 wrote on 2024-10-08, 20:26:

APOPAP wrote on 2024-10-08, 19:32:

Have you tried messing with the bios settings or start just the command prompt ?

yes i messed with every setting. and i tried windows in safe mode.

its ok in Command prompt. I didnt try a dos game yet

Does the external VGA behave just the same as the LCD?
If you can see enough in Windows, try changing the video mode - 640x480 with 256 colours should display a different error pattern than 16-bit colour and 24-bit colour. Something I've found with testing faulty video cards is that 24-bit colour can look much better when there's bad ram

Also, how are you with soldering? I reckon that either a memory chip is bad or you've got a loose pin on the C&T video chip.
regarding my spare 400CDT video card: I'm considering it, I already had a plan for it with another 400CS though

Thermalwrong wrote on 2024-10-12, 02:20:

Does the external VGA behave just the same as the LCD? If you can see enough in Windows, try changing the video mode - 640x480 w […]
Show full quote

renejr902 wrote on 2024-10-08, 20:26:

APOPAP wrote on 2024-10-08, 19:32:

Have you tried messing with the bios settings or start just the command prompt ?

yes i messed with every setting. and i tried windows in safe mode.

its ok in Command prompt. I didnt try a dos game yet

Does the external VGA behave just the same as the LCD?
If you can see enough in Windows, try changing the video mode - 640x480 with 256 colours should display a different error pattern than 16-bit colour and 24-bit colour. Something I've found with testing faulty video cards is that 24-bit colour can look much better when there's bad ram

Also, how are you with soldering? I reckon that either a memory chip is bad or you've got a loose pin on the C&T video chip.
regarding my spare 400CDT video card: I'm considering it, I already had a plan for it with another 400CS though

ok thanks, about your questions, i tried a crt vga monitor on it and its the same graphical glitchs.
I tried all resolution and all color bit. It has glitched in every resolution and bit. I think it looks better in 16bit i didnt see 24bit option. But we decided to heat the ram chips and ct 65546 again but this time it cause some problems. Now the boots screen and bios screen are all full of exclamation point all the screen " ! " so the graphical glitchs are worst. in windows 98 its still similar than before. BUT

Today i got at a pc vintage warehouse another Toshiba 400cdt. But this time its strange. The laptop is really a Toshiba Satellite pro 400cdt, but its very strange, its a pentium 100mhz instead of 75mhz. It has a 800 x 600 11.3 lcd screen. the video card is different its a CT 65550 instead of 65546 with 2mb vram vs 1mb. It has 40mb ram and 6.4gb ide hdd. Everything works even the windows 98 partition.

But we decided to make a big mod with the 2 differents Toshiba satellite pro 400cdt ( we will finish the work tomorrow ) We put the 640 x 480 lcd screen from my first Toshiba 400cdt into the 2nd one Toshiba 400cdt with the pentium 100mhz and better video card ct65550 2mb. And IT WORKS PERFECT ! Now i have a toshiba laptop 400cdt with a pentium 100mhz and a 640 x 480 lcd screen, perfect for playing dos game fullscreen without using stretching or a small square in middle. Wow its miracle it works perfectly without modifying anything. Surprisingly the lcd is brighter than before and more colorful. one of the most bright and colorful lcd screen i have seen in 486 or pentium 1 laptop era. see picture. we will finish the work tomorrow and we will make a effort to mount it to be the more cosmetic beautiful possible.

The video card in each Toshiba 400cdt cant be exchange one with the other because the connector has not the same length and not the same number of contact pins

Thermalwrong, if anytime you change your mind and want to sell the videocard, let me know, i could repair both with it. Thanks 😀

renejr902 wrote on 2024-10-12, 04:59:

ok thanks, about your questions, i tried a crt vga monitor on it and its the same graphical glitchs. I tried all resolution and […]
Show full quote

Thermalwrong wrote on 2024-10-12, 02:20:

Does the external VGA behave just the same as the LCD? If you can see enough in Windows, try changing the video mode - 640x480 w […]
Show full quote

renejr902 wrote on 2024-10-08, 20:26:

yes i messed with every setting. and i tried windows in safe mode.

its ok in Command prompt. I didnt try a dos game yet

Does the external VGA behave just the same as the LCD?
If you can see enough in Windows, try changing the video mode - 640x480 with 256 colours should display a different error pattern than 16-bit colour and 24-bit colour. Something I've found with testing faulty video cards is that 24-bit colour can look much better when there's bad ram

Also, how are you with soldering? I reckon that either a memory chip is bad or you've got a loose pin on the C&T video chip.
regarding my spare 400CDT video card: I'm considering it, I already had a plan for it with another 400CS though

ok thanks, about your questions, i tried a crt vga monitor on it and its the same graphical glitchs.
I tried all resolution and all color bit. It has glitched in every resolution and bit. I think it looks better in 16bit i didnt see 24bit option. But we decided to heat the ram chips and ct 65546 again but this time it cause some problems. Now the boots screen and bios screen are all full of exclamation point all the screen " ! " so the graphical glitchs are worst. in windows 98 its still similar than before. BUT

Today i got at a pc vintage warehouse another Toshiba 400cdt. But this time its strange. The laptop is really a Toshiba Satellite pro 400cdt, but its very strange, its a pentium 100mhz instead of 75mhz. It has a 800 x 600 11.3 lcd screen. the video card is different its a CT 65550 instead of 65546 with 2mb vram vs 1mb. It has 40mb ram and 6.4gb ide hdd. Everything works even the windows 98 partition.

But we decided to make a big mod with the 2 differents Toshiba satellite pro 400cdt ( we will finish the work tomorrow ) We put the 640 x 480 lcd screen from my first Toshiba 400cdt into the 2nd one Toshiba 400cdt with the pentium 100mhz and better video card ct65550 2mb. And IT WORKS PERFECT ! Now i have a toshiba laptop 400cdt with a pentium 100mhz and a 640 x 480 lcd screen, perfect for playing dos game fullscreen without using stretching or a small square in middle. Wow its miracle it works perfectly without modifying anything. Surprisingly the lcd is brighter than before and more colorful. one of the most bright and colorful lcd screen i have seen in 486 or pentium 1 laptop era. see picture. we will finish the work tomorrow and we will make a effort to mount it to be the more cosmetic beautiful possible.

The video card in each Toshiba 400cdt cant be exchange one with the other because the connector has not the same length and not the same number of contact pins

Thermalwrong, if anytime you change your mind and want to sell the videocard, let me know, i could repair both with it. Thanks 😀

Haha someone's done a sneaky label swap, but why??? That's not a 400CDT, the 400CDT only ever came with a 10.4" TFT. 11.3" TFTs were only on the later Satellite Pro 410/420/430 models, which are 800x600 resolution. The 400CDT is desirable specifically because it's 640x480 which neatly scales 320x200 video with the simple scaling that these video chips could do.
edit because I mis-read: The laptop you have there is good but 800x600 doesn't map as well with 320x200 so you'll see some pixel columns are wider than others when you've got LCD expansion turned on. Still quite good for things like Doom and other FPS.

That video chip the CT65550 is in the Toshiba 430CDT / 420CDT / 210CT. The video card doesn't fit because the 400CDT / 410CDT are 'local bus' VL-BUS systems, while the later 420/430 models are actual PCI bus systems

Wait a second, did I read this right. You swapped the screen from the 400CDT onto this new one that is probably a 430CDT and it's displaying 640x480 perfectly???

That's an interesting discovery, I've been meaning to try something along the lines of that for a while since there are LCD ID pins in the LCD cable harness that specify which type of screen to drive which can have 4 variations (2 bits). I go into some more detail on it in the first post in this thread: Upgrading a Toshiba laptop from DSTN to TFT panel - The Satellite 400CS becomes a 400CDT

That means that if you have a broken 400CDT with a bad mainboard or video card, you can take just the screen part (not the video card) and put that on a 430CDT and have a quite fast VGA laptop???
edit: Just been thinking about this, the 430CDT is 1cm longer from front to back than the 400CDT, so you'll also need to remove the LCD hinges and swap over the palm-rest piece otherwise it'll be too short to fit on the 430CDT lower chassis.

Oh also, I recommend to remove those large rectangular green batteries from under the keyboard and ideally remove the smaller green battery as well. Those leak and are the main cause of broken mainboards on the Toshiba Satellite Pro 4xx series.

Thermalwrong wrote on 2024-10-12, 18:35:

Wait a second, did I read this right. You swapped the screen from the 400CDT onto this new one that is probably a 430CDT and it' […]
Show full quote

Wait a second, did I read this right. You swapped the screen from the 400CDT onto this new one that is probably a 430CDT and it's displaying 640x480 perfectly???

That's an interesting discovery, I've been meaning to try something along the lines of that for a while since there are LCD ID pins in the LCD cable harness that specify which type of screen to drive which can have 4 variations (2 bits). I go into some more detail on it in the first post in this thread: Upgrading a Toshiba laptop from DSTN to TFT panel - The Satellite 400CS becomes a 400CDT

That means that if you have a broken 400CDT with a bad mainboard or video card, you can take just the screen part (not the video card) and put that on a 430CDT and have a quite fast VGA laptop???
edit: Just been thinking about this, the 430CDT is 1cm longer from front to back than the 400CDT, so you'll also need to remove the LCD hinges and swap over the palm-rest piece otherwise it'll be too short to fit on the 430CDT lower chassis.

Oh also, I recommend to remove those large rectangular green batteries from under the keyboard and ideally remove the smaller green battery as well. Those leak and are the main cause of broken mainboards on the Toshiba Satellite Pro 4xx series.

Yeah exactly. It works perfectly and it even more bright and colorful. We dont have to made any modification. Read my last post in my other topic. I explained how we will fit all of this, because the back and front plastic around the lcd screen panel wont fit perfectly, but it just plastic 😉

Yeah we will remove both green battery. The 7.2v seems not important because i read it just necessary for standby and i dont put the laptop in standby. But for the other battery that keep cmos setting and time maybe we will put a battery socket in it with a battery model that we can change easily or a great quality brand new battery with the same voltage.

You seem to be sure that the 2nd Toshiba 400cdt cant be a Toshiba 400cdt but a 420cdt or 430cdt instead. Let me know how i can verify that for sure.
Thanks

I don't think the 400 series have the DMI information to determine completely in the OS but you might be able to see something in dxdiag in Windows.

Otherwise, see the specs for the 420CDT here. It has a 100MHz Pentium processor and a CT65550 graphics chip: https://support.dynabook.com/support/staticCo … omTOCLink=false